Cryptographic NIOS II extension with secure key management

Modern security devices are facing many constraints. Besides being efficient in terms of speed and area, they have to achieve high security level and resist against attacks aimed at recovering the secret key. Many common security devices are based on a general-purpose processor (e.g. ARM, PowerPC, NIOS II) realizing communication protocols and a hardware coprocessor dedicated for acceleration of cryptographic algorithms. In this commonly adopted solution, the general-purpose processor operates with secret keys in clear. This way, an intentional or unintentional modification of firmware can lead to secret keys disclosure. In this work, processor cryptographic extension is presented. The platform is based on a NIOS II processor with additional hardware blocks and extended custom instruction set. The aim of this NIOSII extension is to enable highly secure key management. High security level reaches beyond customer electronics, therefore the proposed principle can be employed in automotive or military class devices